The Great Stone Dam (also called the Lawrence Dam or Lawrence Great Dam) was built between 1845 and 1848 on the site of Bodwell's Falls on the Merrimack River in what became Lawrence, Massachusetts. The dam has a length of 900 feet (270 m) and a height of 35 feet (11 m). Today the dam is the site of a hydroelectric plant, completed in 1981, which is owned by Enel (now parent company of the Essex Company, which still owns the dam). and the Lawrence Hydroelectric Associates.